I saw this in Taiwan last year and it looked pretty cool and did in fact seem to amplify my iPhone 4. I balked at the then $29.99 asking price, but now at under $5, it's a hot deal. Makes a great stocking stuffer.
This is the best solution for people that want to use Windows Media Center as their DVR. It's in stock right now, but stock is usually limited and on a first come first served basis. Grab one now.
I have their Dual right now and while setup on FIOS was a bit tricky, its been well worth it.